On the Calendar, you can add an Event directly to instead of needing to add it through the Event Category. To do this:
  1. Select Calendar from one of your Personas (i.e. Faculty, Parent, etc.).
  2. Click Event icon.
  3. Select which Event Category or Group Page to use as the event's Primary category. 
  4. Fill out the Event information.
  5. Publish to additional categories (if desired.)
  6. Click Save.